1. Field of the Invention
This invention is in the field of smelting ore concentrates, particularly sulfide type materials in a first calcining and smelting operation wherein the concentrate is calcined and then smelted, following by an aftertreatment in which the smelt is reduced to produce the metal as a molten layer, with an overlying slag layer, the two layers being capable of separation while still being in the treating furnace.
2. Description of the Prior Art
In a known pyrometallurgical method described in German OS No. 2,348,105, fine-grained sulfur-containing ore concentrates are introduced into a cyclone reactor into which an oxygen-rich gas is blown through a tangentially discharging supply line. The ore concentrate is continuously calcined and melted in the cyclone reactor in the turbulent conditions existing in the reactor. The smelt is collected below the cyclone reactor and consists of a lighter slag phase and a heavier metal phase such as copper matte. This smelt is then metallurgically aftertreated by means of reducing gases which are blown onto the smelt through a lance so that metal oxides which are contained in the slag phase are converted into droplets of metal matte. With such an aftertreatment with reduction gas under these conditions, the lighter slag phase still contains relatively large amounts of metal in admixture with the smelt, so the two mixed phases are withdrawn to another location where they are subsequently separated from each other by means of a separate centrifuge. Beyond the reduction of the oxides, no other aftertreatment of the melt is carried out with the known top blowing technique.